This invention pertains to the methods and devices capable of generating oxygen from water, and more particularly to the generation of oxygen by electrolysis to supplement an otherwise deficient condition, such as when a patient in a hospital is unable to breathe properly, or where the ambient atmosphere is deficient in oxygen, such as at high altitudes.
In hospitals, nursing homes, private homes, and other locations in which sick or elderly patients are cared for, or in aircraft traveling at high altitudes, a source of pure or high concentration oxygen is often necessary to assist in the breathing process. Because sick or elderly patients are sometimes unable to draw enough air into their lungs, the patient""s breathing process is supplemented by the addition of pure oxygen. Because air is only 21% oxygen, the provision of pure or nearly pure oxygen greatly reduces the effort required on the part of the patient to acquire the requisite oxygen for life.
In the past, such oxygen has been supplemented through the use of pressurized tanks and/or liquid oxygen systems. While the tanks have been suitable for their intended purpose, they require pick-up, refilling, and delivery when the initial supply is depleted. In some environments, they also pose a fire hazard.
Some devices have been developed to separate, concentrate, or generate oxygen from ambient air. Many of these devices are based on nitrogen adsorption systems which concentrate oxygen from air to deliver a maximum of 95% O2 by removing nitrogen from ambient air. U.S. Pat. No. 4,449,990 describes one such apparatus. Such devices require a parasitical purging of one tank by pure oxygen from another tank in order to maintain effectiveness. Further, moisture can be damaging to the nitrogen adsorption material.
To overcome the foregoing deficiencies in the art, there is need for a lightweight, quiet, inexpensive device which can generate pure oxygen in quantities small enough to be cost effective for single patient use.
The present invention contemplates a new and improved oxygen generating system which overcomes many of the foregoing difficulties and others while providing better and more advantageous overall results.
Basically, the invention relates to method and a device producing oxygen at ambient temperature from water on demand. The hydrogen which is a by-product of an electrolytic reaction is used in a hydrogen/air fuel cell to produce electrical power water and heat. Condensed water is returned to the water tank for further electrolysis and the produced electrical energy is used in the electrolysis process.
The basic and preferred method of the invention includes the steps:
a) subjecting water to electrolysis, to produce H2 and O2,
b) returning H2 to a water storage zone,
c) drying the produced O2 using air as a drying agent,
d) flowing a stream of that drying agent air to the cathode side of a fuel cell,
e) flowing a stream of produced hydrogen to the anode side of the fuel cell, for reaction with O2 in the agent air to produce water electrical energy and heat,
f) and using electrical energy produced by the fuel cell in said electrolysis.
The method may include: providing a gas dryer through which said O2 and dryer agent air are passed; providing a water storage tank from which water is supplied to the electrolysis; providing a water condenser for receiving the stream of air from the fuel cell, for condensing water from that stream; and/or providing a control system for monitoring electrical power produced by the fuel cell and used in such electrolysis.
Further, the method preferably includes removing water from a stream of air removed from the fuel cell and returning that removed water to the water storage zone, for return to said electrolysis.
These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which: